The discovery phase is not terminated yet (as the Nightly cycle finished Tuesday Sept. 20th); this number will slightly go up (by experience: 5-10%)

We are playing catch-up. In the future we want to be ready by the release of Beta, and we are using the longer 52 cycle to resync. Hence this unusual deadline. Firefox 50.0.1 is the current name of an intermediary release; it may be renamed by the product teams.